Device for tempering rolled stock of great length

ABSTRACT

The invention relates to a device for the thermal tempering of at least parts of the cross section over the lengthwise extension of sequentially produced profiled rolling stock from the rolling heat.  
     In order to attain a high quality and good use properties of the rolling stock passed through the thermal tempering device using the rolling heat from the lines of rollers with high output, it is provided according to the invention for the roller table ( 1 ) to have a device for positioning the supplied rolling stock (S) in the lengthwise direction and an assigned aligning means ( 2 ), for the hardening device ( 3 ) to be formed of at least two liquid cooling devices ( 31, 32 ), arranged next to one another, with manipulators ( 311, 311′ ) for a movement of the rolling stock (S), for the deposit region ( 41 ) of the cooling bed ( 4 ) to be located next to, and parallel to the lengthwise extension of, the liquid cooling devices, and for the means ( 5 ) for transport in transverse direction to have at least two supporting arms ( 51 ) that are simultaneously movable between the rolls of the roller table, each having end-side rolling stock rests ( 52 ) arranged thereon.

[0001] The invention relates to a device for the hardening of rollingstock having a large lengthwise extension at a high throughput. Moreprecisely defined, the invention relates to a device for the thermaltempering of at least portions of the cross section over the lengthwiseextension of sequentially produced profiled rolling stock from therolling heat, in particular for hardening at least the head of railshaving a length greater than 50 m, and subsequent cooling to roomtemperature, consisting essentially of a roller table, a means forarranging the rolling stock in axial alignment, a transport means havinga rest for the rolling stock for the transport thereof in transversedirection, a hardening device with a manipulation arrangement, and acooling bed.

[0002] In order to improve the properties of the material, a rollingstock is usually subjected to a thermal tempering treatment thatadvantageously is carried out with the use of the rolling heat. Thistempering, which essentially affords an increase in the mechanicalproperties of the material such as hardness, abrasion resistance, andthe like, can be performed over the entire cross section or, as iscommon with a running rail, only over partial sections of the same.Here, the rolling stock which is in its austenitic microstructuralstate, or partial sections of the cross section of the same, is dippedinto a cooling medium over its entire length and, in this manner, atransformation of the microstructure is achieved in the desired manner.

[0003] Devices for carrying out such tempering processes are known(EP-0441766 B1) and have proven suitable with regard to an improvementof the use properties of railroad rails.

[0004] Depending on the final rolling temperature and depending on thespecific mass or mass per length unit, respectively, of the rollingstock, thermal tempering thereof requires a corresponding submersiontime or residence time in the cooling liquid, such that the throughputthrough the tempering device is limited. In other words, the maximumpossible throughput through a submersion tempering installation with acooling basin limits the output of the rolling device arranged beforeit.

[0005] Modern roll-forming lines with prearranged heating furnacesparticularly for continuous casting input stock usually have potentialrolling outputs that are greater than the throughput of known submersiontempering installations, so that with a sequential production ofhardened rails, the rolling output has to be reduced.

[0006] In order to avoid this disadvantage, which is in particular aneconomic one, it has already been recommended to temper the rollingstock as it moves through a cooling path provided with spraying means.However, this continuous pass process requires long lengths of theinstallation and usually does not result in the required materialquality of the rolling stock.

[0007] The invention aims at avoiding the deficiencies and, inparticular, the economic disadvantages, of known thermal treatmentinstallations for rolling stock of the type mentioned at the outset andat providing a device that ensures a high quality and good useproperties of the rolling stock produced and has a high output andrenders possible the treatment and thermal tempering of sequentiallyproduced bar stock, particularly of rails having lengths of more than 50m, on roll lines with high output while using rolling heat.

[0008] This goal is attained in a generic device in that the rollertable has a device for longitudinally positioning the rolling stockwhich is supplied supported in at least one cross-sectional region, andan assigned alignment means, in that the hardening device is formed ofat least two liquid cooling devices arranged next to one anotheressentially parallel in their lengthwise direction to the alignmentmeans with manipulators for a movement of the rolling stock, in that thedeposit region of the cooling bed is located next to, and parallel tothe lengthwise extension of, the liquid cooling devices, and in that themeans for transport in transverse direction has at least two supportingarms that are simultaneously movable between the roller table rolls,each having rolling stock rests arranged on the end side, that theserests on the supporting arms can be moved in transverse direction fromthe alignment position in the region of the roller table into thedeposit region of the cooling bed, lowered, and raised in such a waythat exclusively the rests protrude beyond the transport surface of theroller table and the upper edge of the roller table, respectively.

[0009] The advantages attained by the invention lie especially in thefact that, using the device, it is possible to position and axiallyalign the rolling stock in a simple manner in sequence in the transversetransport region of the roller table with a high degree of precision, itbeing possible, by means of the rolling stock rests of the means fortransport in transverse direction, to simultaneously, i.e., withoutinterfering with the adjustment and the axial alignment process,transport a previously aligned and provided piece of rolling stock intothe deposit regions of the cooling devices or from there into thedeposit region of the cooling bed or from the roller table directly ontothe cooling bed. In this connection, it is important that only therolling stock rests of the supporting arms of the means for transport intransverse direction, which arms are movable between the rolls, arecapable of being raised above the upper level of the rolls of the rollertable or their transport surface, respectively. With this embodiment ofthe device, it is possible to arrange at least two hardening devices onone side of the roller table such that a cooling bed must be provided onone side only, which yields economic advantages. A piece of rollingstock that is positioned on the roller table and axially aligned can belifted off the roller table by means of the rests of the supporting armsand, for example, be laid down in a deposit region of a liquid coolingdevice that is embodied as a manipulator. Thereafter the means fortransport in transverse direction is freed up for transporting furtherpieces of rolling stock, where the manipulator can, alone andindependently, orient the deposited rolling stock in its cross-sectionalposition, place it in the cooling medium at least partially, lift itout, and provide it for transport to the cooling bed. This separation ofthe transport in transverse direction of the rolling stock, which isessential to the invention, even past occupied cooling devices with,eventually, a deposit on the cooling bed, and a precise placement of therolling stock in the cooling medium improves the precision of themanipulation as well as of the cooling treatment and reliably affordshardened rolled products with consistently high quality. In anadvantageous and economical manner, the output and throughput,respectively, of the device is approximately doubled when using twohardening devices next to one another.

[0010] If the device is intended for a rolling stock in the form of arunning rail or a railroad rail that rests on the roller table in twocross-sectional regions and the positioning device is embodied as anelectronically controllable means and/or has an alignment bar or alateral stop, it is possible in a favorable fashion for the residencetime of the rails on the roller table to be reduced, for the temperaturecontrol to be improved, and, optionally, for the output of theinstallation to be increased. Moreover, this position is particularlywell suited for a so-called “head down” vertical positioning of the railby means of the manipulators.

[0011] If, as may be provided in one embodiment of the invention, theliquid cooling devices are formed as submersion basins that havehorizontally and vertically oriented stops acting on the bottom and,optionally, laterally for leveling and aligning the rolling stock, it ispossible, in particular in the case of the cooling of parts of the crosssection of a rail, for a highly consistent cooling and distribution ofhardness to be achieved over its length, which helps to ensure thequality of the product.

[0012] It is advantageous for consistent and good use properties ifholding-down means for the rolling stock, in particular for a rail, areprovided in the device, with which means the rolling stock/rail can bepressed down against the leveling stops in the submersion basin duringcooling because this can effectively prevent a bending caused by thecooling and keep the respective local cooling of the surface completelyconstant.

[0013] Particular economic advantages are provided by using the devicedescribed above for hardening at least the head of rails having a lengthof greater than 50 m and subsequent cooling to room temperature at apass-through time of a rail through the hardening device that exceedsthe supply frequency because large increases in performance are possibleat comparably low investment costs.

[0014] In the following, the invention will be described with referenceto a drawing which shows one embodiment only, with the referencecharacters, each of which is kept the same, being listed below.

[0015] List of Reference Characters:

[0016] S Rolling stock

[0017]1 Roller table

[0018]11 Transport surface of the roller table

[0019]2 Alignment means

[0020]21 Alignment bar

[0021]3 Hardening device

[0022]31 Liquid cooling devices

[0023]32

[0024]311 Manipulators

[0025]321

[0026]312 Submersion basins

[0027]322

[0028]313 Leveling stops

[0029]323

[0030]314 Holding-down means

[0031]324

[0032]315 Cooling liquid

[0033]325

[0034]4 Cooling bed

[0035]41 Deposit region of the cooling bed

[0036]5 Means for transport in transverse direction

[0037]51 Supporting arm

[0038]52 Rolling stock rest

[0039]FIG. 1 shows a device according to the invention with a hardeningdevice 3 consisting of two liquid cooling devices 31 and 32 that arearranged between a roller table 1 and a cooling bed 4. In the exemplaryschematic depiction, the head of the rail S is shown submerged in acooling liquid 315 in one of the liquid cooling devices 31. By means ofholding-down means 314 and leveling stops 313, the rail can bepositioned in a submersion basin 312 in such a way that precisely onlyan accelerated head cooling of the same takes place. However, usingstops 313 positioned farther below the surface of a cooling liquid 315,it is also possible to cool the entire cross section of the rail in anaccelerated manner. A second liquid cooling device 32 stands ready.

[0040] As FIG. 1 further shows, a rail S coming from a line of rollers(not shown) is positioned on the roller table 1 and can be arranged withits axis aligned by means of an alignment means 2 optionally having analignment bar 21. A means 5 for transport in transverse direction withsupporting arms 51 and one rolling stock rest 52 each is arranged suchthat it can be moved back into the region of the roller table 1.However, it is also possible to establish such a means 5 for transportin transverse direction in the region of the cooling bed.

[0041] For transport in transverse direction, a simultaneousdisplacement of the supporting arms 51 is carried out in such a way thatthe rolling stock rests 52 arranged thereon, when raised, can lift therail S off the roller table 1 in an axially aligned manner, carry it,and move it transversely in the direction of the cooling bed 4. Here, itis essential to the invention that, in the course of a transport intransverse direction, exclusively the rolling stock rests 52 of themeans 5 for transport in transverse direction can vertically protrudeabove a transport surface 11 of the roller table, even if the deposits52 are moved into the outermost opposing region, for example, whenplacing a rail S on a deposit region 41 of the cooling bed 4.

[0042] A positioned and axially aligned rail S, which lies on thetransport surface 11 of the roller table 1, advantageously in twocross-sectional regions, can now be vertically lifted in this positionby means of the rolling stock rest 52 and be moved essentiallyhorizontally or transversely to a stand-by liquid cooling device in FIG.1, item 32. Such a cross-sectional position of the rail S on the rollingstock rests 52 is favorable for reception of the same and a “head down”vertical positioning by means of a manipulator 321, by means of which alowering or introduction of the rail head into a cooling liquid 325 canbe carried out as well. During the residence time of the rail in thecooling liquid 325, the rail can be clamped by means of holding-downmeans 324 and leveling stops 323 for the purpose of stabilization.

[0043] Because, as previously mentioned, according to the invention,exclusively the rolling stock rests 52 can be brought to a level thatlies above the transport surface 11 of the roller table 1, it ispossible, despite transverse transport activities, to bring a subsequentrail from the rolling works onto the roller table 1 and to position andalign it thereon. The removal of a rail S from the liquid coolingdevices 31, 32 by means of manipulators 311, 321 and a taking offthereof by means of the rolling stock rests 52 can be carried out inessentially the same manner, whereupon a transport and deposit onto thedeposit region 41 of the cooling bed 4 take place.

[0044] In the case of high rolling output, the hardening device 3 canalso be equipped with more than two liquid cooling devices, but aprogrammable control unit may advantageously be used for a productionsequence.

1. Device for the thermal tempering of at least parts of the crosssection over the lengthwise extension of sequentially produced profiledrolling stock from the rolling heat, in particular for hardening atleast the head of rails having a length of greater than 50 m, andsubsequent cooling to room temperature, consisting essentially of aroller table, a means for axially aligning the rolling stock, atransport means having a rest for the rolling stock for transporting thesame in transverse direction, a hardening device with a manipulatorarrangement, and a cooling bed, characterized in that the roller table(1) has a device for positioning in longitudinal direction the rollingstock (S) which is supplied thereto supported in at least onecross-sectional region, and an assigned alignment means (2), in that thehardening device (3) is formed of at least two liquid cooling devices(31, 32), arranged next to one another essentially parallel to thealignment means, with manipulators (311, 331) for a movement of therolling stock (S), in that the deposit region (41) of the cooling bed(4) is located next to, and parallel to the lengthwise extension of, theliquid cooling devices, and in that the means (5) for transport intransverse direction has at least two supporting arms (51) that aresimultaneously movable between the rolls of the roller table, each armhaving end-side rolling stock rests (52) arranged thereon, these restson the supporting arms are movable in the transverse direction from thealignment position in the region of the roller table (1) into thedeposit region (41) of the cooling bed (4) and can be raised in such away that exclusively the rests protrude beyond the transport surface(11) of the roller table (1).
 2. Device according to claim 1,characterized in that it is intended for a rolling stock (S) in the formof a running rail or railroad rail that is supported on the roller table(1) in two cross-sectional regions, in that the positioning device isembodied as an electronically controllable means, and/or has analignment bar (21) or a stop.
 3. Device according to claim 1 or 2,characterized in that the liquid cooling devices (31, 32) are embodiedas submersion basins (312, 322) that have horizontally aligned stops(313, 323) which act on the bottom and, optionally, laterally forleveling the rolling stock (S).
 4. Device according to claims 1 to 3,characterized in that manipulators (311, 321) are assigned to eachsubmersion basin (312, 322), by means of which the rolling stock (S), inparticular a rail, can be taken off the rests (52) of the means (5) fortransport in transverse direction, introduced, alignable vertically,“head down”, into the submersion basin (312, 322), and placed on therests (52) again.
 5. Device according to one of claims 1 to 4,characterized in that holding-down means (314, 324) are provided for therolling stock (S), in particular a rail, with which means the rollingstock/rail (S) can be pressed down against the leveling stops (313, 323)in the submersion basin (312, 322) during cooling.
 6. Use of the deviceaccording to one of claims 1 to 5 for hardening at least the head ofrails with a length of greater than 50 m and subsequent cooling to roomtemperature at a pass-through time of a rail through the hardeningdevice that exceeds the supply frequency.